In Ontario and elsewhere, prosecutions of on-duty police officers are considered among the most difficult cases in the criminal justice system, and Crown attorneys assigned to such cases are accustomed to losing.

“It’s inappropriately hard to get officers charged and convicted,” says defence lawyer Peter Rosenthal, who has represented families of people fatally shot by police.

“The remarkable thing about the (Sammy) Yatim case is the video, but that’s not a change in general procedures or general attitudes.”

On Tuesday, Toronto police Const. James Forcillo was released on bail after being charged with second-degree murder in the death of the 18-year-old on a TTC streetcar last month.

Toronto Police Association president Mike McCormack acknowledges that many officers charged with crimes are ultimately found not guilty, but says that’s for good reason.

“It’s like any other case. The evidence has to be there to support the charge; if there’s no evidence, so be it,” he said Tuesday.

“People have a misconception that we get preferential treatment. And in fact it’s different; there’s a lower threshold when they charge us, and that’s why, often, police officers aren’t convicted.”

And, he added, “by the nature of our jobs we’re compelled to do things that put us in situations where we could be exposed to criminal charges.”

Others, however, believe that in police prosecutions, the cases are stacked against the Crown. Judges and juries are inclined to regard cops as being of good character, and sympathize when officers are charged while on duty protecting the public.

When officers are charged with corruption, invariably the witnesses will have criminal records, creating a huge credibility imbalance in court.

In police shootings, there may be those who, rather than blaming the officer, point the finger at the system for not providing better training or Tasers for every officer.

Then there’s the thin blue line.

In many cop cases, the only other witnesses besides the accused officer are the witness officers, “and they don’t tend to provide evidence that’s helpful to the prosecution,” Rosenthal said.

He also credits the frequency of cop acquittals to the formidable legal talents who represent officers — in Forcillo’s case, prominent defence lawyer Peter Brauti.

“Police officers charged with crimes are invariably represented by officers paid for by the Toronto Police Association. They’re good lawyers who are paid well.”